A drum-type drying machine supplies high-temperature hot air into a drum while rotating in one direction to dry laundry. When laundry, such as a bed sheet, having a wider area and a lighter weight is contained in the drum, a laundry tangling frequently occurs in which the laundry having a wider area surrounds laundry having a smaller area in a drying process, which is called a Santa Bag. When the Santa Bag occurs, a dryness sensor mounted in the drum may not exactly sense the dryness of the laundry.
In other words, even though the laundry contained in the drum is not sufficiently dried, only the dryness of the laundry surrounding the laundry having the smaller volume may be sensed. In this case, even though the laundry is not sufficiently dried, a controller of the drying machine may erroneously determine that a drying completion time almost comes.
A conventional laundry processing apparatus disclosed in Korea Unexamined Patent Publication No. 2010-0031865 controls the drying drum to periodically and alternately perform forward rotation and reverse rotation to prevent or minimize the laundry tangling.
As described above, if the drying drum periodically repeats the forward rotation and the reverse rotation in the drying process, the laundry tangling may not be prevented from occurring significantly frequently under a specific condition. In addition, once the laundry tangling occurs, the laundry tangling may not be improved for a reverse rotation time according to the related art.
In addition, if the drying drum frequently rotates reversely, an amount of wind introduced into the drying drum is reduced, so the drying efficiency may be degraded. For example, in the case of a drying machine including a drying drum, which is coupled to a one-side rotational shaft of a driving motor through a pulley and a belt, and a drying fan mounted on an opposite-side rotational shaft of the driving motor, when the driving motor rotates reversely, the drying fan may move reversely to prevent hot air from being introduced into the drying drum or an amount of hot air to be introduced may be reduced.